JPH0821775A - Pressure sensor - Google Patents

Abstract

PURPOSE:To provide a pressure sensor which realizes an electric connection between strain gauge and printed board without being influenced by vibrations and shocks at diaphragm. CONSTITUTION:The pressure sensor is provided with a connection mouth body 2 on a press-receiving side which has a diaphragm 8 at the end face and a strain gauge 9 n the surface of the diaphragm 8, an intermediate body set to surround the strain gauge 9, and a connection mouth body 4 on the signal side which is to be engaged with the end face side of the connection mouth body 2 to cover the opening of the intermediate body. A printed board 21 is arranged at the intermediate body. Moreover, the printed board 21 is electrically connected with the strain gauge 9 by a terminal element 14 projecting from the strain gauge 9 and a conductive part at an edge of the printed board 21 sliding in touch with the terminal element 14. Accordingly, vibrations and shocks generated at the diaphragm 8 are not transmitted directly to the printed board 21. At the same time, the vibrations and shocks are absorbed through a relative shift of the terminal element 14 and the conductive part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure sensor for detecting the pressure of a fluid flowing through a pipe or the like.

[0002]

2. Description of the Related Art In a system having pressure piping, for example, an air conditioner for an automobile, a predetermined control is performed by using a refrigerant pressure in a refrigeration cycle. A pressure sensor is used to detect such fluid pressure.

A pressure sensor of this type is usually composed of a main body divided into two, as disclosed in Japanese Patent Application Laid-Open No. 2-503831, and one of the main bodies is a side receiving a fluid pressure and the other is a side. A structure in which an output voltage signal corresponding to the pressure is output is used.

Specifically, the side receiving the pressure of the fluid has a pressure introducing port (not shown) at one end as shown in FIG. 10, and a strain gauge a is formed on the other end surface. It comprises a pressure receiving side connection port body c having a diaphragm b adhered and fixed thereto.

The side for outputting a signal is composed of a signal side connection port body d which is combined with the end face of the pressure receiving side connection port body c. By the way, the pressure sensor amplifies the output from the strain gauge a which is distorted by the displacement of the diaphragm b and outputs it to the outside.

[0006] The patent application publication No. Hei 2-5038
As disclosed in No. 31, a printed circuit board on which electronic components necessary for amplification are mounted is provided inside the sensor, and the printed circuit board has a strain gauge and a terminal portion ( Electrical connection is being made between external devices and connectable terminals).

Specifically, as shown in FIG. 10, a recess f is formed in the end face of the signal side connecting port body d corresponding to the strain gauge a, and a device accommodating chamber is provided around the strain gauge a. form g.
A plurality of clips h formed in a substantially U shape are soldered on the peripheral portion of the strain gauge a, and the edges of the printed circuit board i are fitted to these clips h to form the printed circuit board i. The entire device is housed in the device housing chamber g, more specifically above the strain gauge a.

The tip of the clip h has a printed circuit board i.
Clip h that is soldered to and holds the printed circuit board i
Is used to electrically connect the printed circuit board i and the strain gauge a. The printed circuit board i and the terminal of the signal side connection port body d are electrically connected by a connection portion structure not shown.

[0009]

The diaphragm b of such a pressure sensor structurally exhibits a behavior in which vibration, impact, etc. occur due to a change in fluid pressure. However, in the structure in which the printed circuit board i is held by the strain gauge a on the surface of the diaphragm b via the clip h, the vibration and shock of the diaphragm b cause the clip h holding the printed circuit board i. Soldering part j, and further printed circuit board i
To be transmitted as is.

Therefore, under the influence of the generated stress,
There is a risk that the solder of the soldering portion j and the solder of the printed circuit board i may be peeled off from the strain gauge a and the printed circuit board i, or cracks may be generated.

Particularly when used for automobiles, even when external vibration or shock is applied or a large temperature change is applied, stress is similarly generated in the soldered portion, which may cause a defect in the soldered portion. there were.

When this happens, the conductive path from the strain gauge a to the printed circuit board i is damaged, and the pressure sensor may not function properly. The present invention has been made in view of such circumstances, and an object thereof is to provide an electrical connection between a strain gauge and a printed circuit board, which is not affected by vibration or shock generated in a diaphragm. It is to provide a pressure sensor that can be realized.

[0013]

In order to solve the above-mentioned problems, the invention according to claim 1 has a diaphragm on its end face which is displaced by receiving pressure from a pressure introducing port, and which is the same on the surface of this diaphragm. A pressure receiving side connection port body having a strain gauge for detecting the strain of the diaphragm, and an end face portion of the pressure receiving side connection port body provided so as to surround the circumferential side of the strain gauge. A short tube-shaped intermediate body is provided in combination with the end face side of the pressure receiving side connection port body so as to cover the opening of the intermediate body, and forms a device-accommodating chamber whose periphery is closed in the intermediate body. A signal side connection body having a terminal connectable to a device,
A printed circuit board fixed to the intermediate body and arranged in the device accommodating chamber, on which electronic components are mounted, and a first connection portion for electrically connecting the printed circuit board and the terminal of the signal side connection port body. A second connecting portion electrically connecting the strain gauge and the printed circuit board by sliding contact with two sliding contact members that are in sliding contact with each other in a direction substantially perpendicular to the direction in which the diaphragm is displaced. And having a pressure sensor.

According to a second aspect of the present invention, in order to achieve the above object with a simple structure, the strain gauge has the second connecting portion according to the first aspect. A terminal piece extending in the direction in which the diaphragm is displaced from the terminal portion to the printed circuit board, and a conductive portion which is provided in the printed circuit board and is in sliding contact from a direction substantially perpendicular to the direction in which the terminal piece and the diaphragm are displaced. I have configured it.

According to a third aspect of the present invention, in addition to the above object, the first aspect of the present invention enables connection between the printed circuit board and the signal-side connection port without applying stress to the printed circuit board.
The first connecting part described in 1) is electrically connected to the terminal, and has an insertion part protruding toward the intermediate body from a surface facing the opening of the intermediate body of the signal-side connection port body, and is provided in the intermediate body. It is configured to have a receptacle portion into which the insertion portion is inserted according to the mounting of the signal-side connection port body, and a displaceable conductive member that electrically connects the receptacle portion and the printed board. .

In addition to the above object, the invention according to claim 4 further provides a strain gauge on the diaphragm with high accuracy and without any installation problem such as peeling. The strain gauge described in 1 is constituted by directly forming a gauge pattern on the surface of the diaphragm.

According to a fifth aspect of the invention, in addition to the above object, in order to realize a male screw type pressure sensor without a leak, the pressure receiving side connection port body according to the first aspect is made of metal. By forging the member, the inner passage is formed into a bag shape with a large passage end facing the diaphragm side and a small passage end communicating with the pressure inlet, and the outer periphery of the mouth where the pressure inlet is formed. This is because the screw part is formed on the part.

In addition to the above, the invention according to claim 6 further comprises a pressure receiving side connection port body, which does not require a separate connecting means.
In order to enable the three members of the intermediate body and the signal side connection port body to be coupled, the pressure receiving side connection port body is extended to the outer peripheral portion of the main body portion concentrically with the main body portion and the intermediate portion. And a peripheral portion of the signal receiving side connection port body, which has a thin metal tubular body covering the periphery of the signal receiving side connection port body, the distal end portion being deformed at the tip end portion of the tubular body. It is configured to have an engaging portion that engages.

[0019]

According to the first aspect of the present invention, the printed circuit board is independently provided not as the strain gauge but as an intermediate body which is separate from the strain gauge. At the same time, the same printed circuit board and strain gauge
It is connected to the electric connection via two sliding members which are slidable in the direction in which the diaphragm is displaced.

As a result, the vibration generated in the diaphragm,
Impact is not directly transmitted to the printed circuit board. Moreover, the vibrations and shocks generated by the diaphragm are absorbed by the relative displacement of the two sliding members that electrically connect the strain gauge and the printed circuit board.

This means that the stress generated on the printed circuit board is suppressed to a minimum, peeling of the solder that has been soldered as in the conventional case and the occurrence of cracks are avoided, and printing is performed from the strain gauge. Maintain a good conductive path to the substrate.

According to the second aspect of the invention, the simple structure in which the conductive member provided on the printed board and the terminal piece protruding from the strain gauge are in sliding contact with each other can absorb the vibration and shock generated in the diaphragm, Maintains a good conductive path between the printed circuit board and the strain gauge.

According to the third aspect of the invention, as the signal side connection port body is combined with the pressure side connection port body, the receptacle in which the insertion portion protruding from the inner surface of the signal side connection port body is present in the intermediate body. The printed circuit board and the terminal mounted independently of each other are electrically connected to each other.

At this time, since the receptacle portion and the printed circuit board are connected via a displaceable conductive member, a shock or the like generated at the time of connection is absorbed by the displacement of the conductive member to print. It does not reach the board.

As a result, the printed circuit board and the signal side connection port can be connected without applying stress to the printed circuit board. According to the invention as set forth in claim 4, the strain gauge is highly accurately formed on the surface of the diaphragm by the direct formation.
In addition, a strain gauge is formed on the diaphragm without problems such as peeling.

According to the fifth aspect of the present invention, the pressure sensor having the threaded portion at the tip is assembled without the need for an additional adapter. This means that there is no possibility of creating a gap like the structure that assembles the screw type pressure receiving side connection port by connecting the adapter and the pressure receiving side connection port, and there is no fluid leak. There is no.

According to the sixth aspect of the invention, the pressure receiving side connecting port body is assembled to the end side of the signal receiving side connecting port body so as to cover the periphery of the intermediate body and the signal receiving side connection port body with the tubular body. In addition, if the end portion of the tubular body is deformed and the same portion is engaged with the outer peripheral portion of the signal receiving side connection port body, the pressure receiving side connection port body, the intermediate portion without the need for a separate coupling means. The body and the signal-side connection body are connected.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the first embodiment shown in FIGS. 1 is an external view of a pressure sensor to which the present invention is applied, FIG. 2 is an exploded perspective view of the pressure sensor,
FIG. 4 is a sectional view of the same pressure sensor, FIG. 4 is a sectional view of the same pressure sensor, and FIG. 5 is an exploded sectional view of the same pressure sensor, in which 1 is a main body.

As shown in FIGS. 2 and 5, the main body 1 includes a pressure receiving side connecting port body 2, an intermediate body 3, and a signal receiving side connecting port body 4.
And these three parts are combined in series in the axial direction to form the whole.

That is, as shown in FIG. 4, the pressure receiving side connection port body 2 is formed of a metal member, for example, SUS or an aluminum alloy, into a cylindrical shape with a bottom, and most of the pressure receiving side connection port body from the open end to the base end side. A hexagon nut portion 5 having a female screw portion 5a on the inner surface is provided at the occupied portion, for example. The open end of the hexagon nut portion 5 serves as the pressure introducing port 6 and the internal space serves as the passage 7.

Further, the pressure receiving side connection port body 2 facing the passage 7
A diaphragm 8 formed by thinly forming the bottom wall portion is formed on the bottom wall portion. Of course, the thickness of the diaphragm 8 is set to such a thickness dimension that the pressure change of the fluid flowing from the pressure introducing port 6 can be sensed (displaced).

A strain gauge 9 is formed on the surface of the diaphragm 8.
Is provided. The strain gauge 9 is directly formed on the diaphragm 8 as shown in FIG. 7 so as to be attached to the diaphragm 8 with high accuracy without error.

More specifically, the insulator 10 is provided on the surface of the diaphragm 8 by fixing and hardening the insulating film.
On the surface of 0, a gauge pattern 11 is formed by vapor deposition and etching of copper and copper alloy, and a protective film 12 is further provided on the gauge pattern 11 to form a strain gauge 9.

Further, at a portion near the outer periphery of the strain gauge 9, four terminal portions 13 are formed in a row along the diameter direction as shown in FIGS. These terminal parts 1
3, for example, terminal pieces 14 (one sliding member) are provided so as to protrude in a line in the same direction.

More specifically, the terminal piece 14 is composed of, for example, a leaf spring bent in a substantially inverted L shape, and has a lateral portion 14a.
The plate surface portion of is soldered to the terminal portion 13. Then, by this soldering, the longitudinal portion 1 of each terminal piece 14 is
4b is arranged in a direction parallel to the direction in which the terminal portions 13 are arranged so as to project toward the direction in which the diaphragm 8 is displaced.

Reference numeral 15 indicates a fixing collar portion provided on the outer peripheral portion of the hexagonal nut portion 5 on the base end side, and 25 indicates solder to which the terminal piece 14 is fixed (only shown in FIG. 7). Also Intermediate 3
Has a body portion 16 formed from an insulating material, for example, a synthetic resin member, into a short tubular shape.

As shown in FIGS. 4 and 5, one end of the main body 16 has an inner diameter corresponding to the outer diameter of the base end of the pressure receiving side connection port 2 and an outer shape of the flange 15. A circular large diameter portion 17 having a corresponding outer diameter dimension is formed.

The large diameter portion 17 is removably fitted into the base end portion of the pressure receiving side connection port body 2. The length of the large diameter portion 17 is set to be longer than the distance from the end of the strain gauge to the collar portion 15, and most of the large diameter portion 17 is projected upward from around the strain gauge 9. ing.

The other end of the protruding main body 16 is
The circular small diameter portion 18 has an outer diameter smaller than that of the large diameter portion 17. As shown in FIGS. 2 and 3, a rectangular opening 19 is formed in the small diameter portion 18 at a position deviated from the center, and the periphery of the strain gauge 9 is surrounded by the large diameter portion 17 and the small diameter portion. 1
Surrounded by 8 and.

In the rectangular opening 19, a rectangular printed board 21 on which various electronic components 20 constituting an amplifier circuit are mounted is fixed. More specifically, as shown in FIG. 6, among the peripheral walls forming the rectangular opening 19, for example, the lowest part of the pair of wall parts on both ends of the terminal strip, the bottom part of the printed circuit board 21 is provided. A seat 22 for receiving the edge is provided so as to project inward.

At the center of each wall portion, a pair of lever pieces 23 are formed by molding the wall portion into a strip plate shape extending from the upper side to the lower side. The lever piece 23 has a spring property (elasticity) that is displaced in the front-rear direction with the upper end portion connected to the wall portion as a fulcrum.

Further, a projection 23a is formed on the lower front surface of each lever piece 23 at a position apart from the seat 22 by the thickness dimension of the printed board 21, so that the printed board 21 contacts the seat 22. The printed board 21 on the receiving seat 22 is held so as not to come out by the projection 23a on the lever piece 23 that elastically returns by being fitted into the opening 19 until it contacts.

A recess 24 for forming a gap with the edge of the printed board 21 is formed in the wall of the opening 19 which is in the same direction as the terminal piece 13 of the strain gauge 9. . As a result, when the intermediate body 3 is mounted on the pressure receiving side connection port body 3, the tip end portion of the terminal piece 13 rising from the strain gauge 9 (the tip end portion of the longitudinal portion 14b) is located at the edge portion of the printed circuit board 21. Then, the inside of the recess 24 is inserted.

Printed circuit board 2 touched by these terminal pieces 13
Each terminal piece 13 and the diaphragm 8 are attached to each edge portion of 1.
Conductive part 25 slidingly contacting from the direction perpendicular to the displacement direction
(Corresponding to the other sliding contact member and the conductive member) are respectively formed so that the displacement generated in the diaphragm 8 can be absorbed between both the printed circuit board 21 and the strain gauge 9.
Electrically connected so that relative displacement is possible (second connection portion).

The tip of the terminal piece 13 (longitudinal portion 14
The tip portion b) is elastically brought into contact with the conductive portion 25. Alternatively, the contact portions may be connected by soldering if necessary.

The small-diameter portion 1 on the side opposite to the conductive portion 25
As shown in FIG. 3, a plurality of, for example, three receptacle portions 26 are embedded on the upper surface of the flat portion 3a of 8 at predetermined intervals with the connection ports 26a facing upward. Is. Of course, the connection port 26a of each receptacle 26 opens from the upper surface of the flat portion 3a.

Each receptacle portion 26 is integrally provided with a leaf spring portion 27 (conductive member) extending toward the printed circuit board 21 as shown in FIGS. The leaf spring portion 27 is formed in, for example, a substantially stepped shape, and constitutes a displaceable portion 28 for releasing an external force at the portion.

The tip end of the leaf spring portion 27 is soldered to the conductive portion 29 provided on the upper surface of the edge portion of the printed board 21 so that the receptacle portion 26 and the printed board 21 can be electrically displaced. Connected.

The intermediate body 3 has a portion 18a of the small-diameter portion 18 where the lever piece 23 is present in order to have a positioning function.
Is partially higher than the other parts, and is also small-diameter portion 1 existing between the lever piece 23 and the receptacle portion 26.
A pair of stepped portions 30 is formed on the outer peripheral portion of 8.

The signal receiving side connection port body 4 has a main body 31 molded from an insulating material such as a synthetic resin member. As shown in FIGS. 1 and 2, the main body portion 31 has a cap portion 3 that can be inserted into and removed from the small diameter portion 18 of the intermediate body 3 at one end portion.
2 and has an elliptic cylindrical connection case 33 at the other end. The outer diameter of the cap portion 32 is set to be the same as that of the large diameter portion 17 of the intermediate body 3.

This cap portion 32 is the small diameter portion 1 of the intermediate body 3.
8, the signal side connection port body 4 is attached to the opening 1 of the intermediate body 3.
It is combined with the pressure side connection port body 2 so as to cover 9. The equipment accommodating chamber 35 is formed by utilizing the space in the intermediate body 3 whose periphery is closed. And this equipment storage room 3
As described above, the printed circuit board 21 is arranged in the predetermined space 5 by utilizing the intermediate body 3.

Further, on the inner bottom surface of the cap portion 32, a pair of protrusions (not shown) which are combined with the step portion 30 in the intermediate body 3, and a pair of concave portions 34 which are also combined with the raised portion 18a (see FIG. 5) is formed, and the intermediate body 3 and the signal receiving side connection port body 4 are connected to each other in a predetermined manner only when the direction in which the receptacle portions 26 are arranged and the longitudinal direction of the connection case 33 are aligned. I am doing it.

That is, the orientation of the connection case 33 is determined in the same direction as the orientation of the receptacle portions 26. Within the connection case 33, a plurality of, for example, three terminal portions 36 (corresponding to terminals) are fixed side by side in the longitudinal direction at the position of the receptacle portion 26.

Each of the terminal portions 36 has a portion 37 for external connection, which is exposed from the inside of the connection case 33 to the outside. Further, the other end of each terminal portion 36 is provided with an inverted L-shape, that is, a relay portion 38a along the inner bottom surface of the cap portion 32 and an insertion portion 38b that descends from the inner bottom surface toward the receptacle portion 26 side. Insert piece 3 to have
8 (corresponding to the insertion portion) is formed.

Each insertion portion 38b has a receptacle portion 26.
The length is set so that the cap portion 32 and the intermediate body 3 are connected to each other.
The terminal portion 36 and the printed circuit board 21 are electrically connected to each other through the receptacle portion 26 (first connection portion).

Then, the pressure receiving side connecting port body 2, the intermediate body 3, and the signal receiving side connecting port body 4 which have the same diameter and are assembled in series are formed.
Around the periphery of the connector, a connecting tool, for example, a color 39 molded into a cylindrical shape with an aluminum member is inserted, and the three parts are coupled so as not to come off.

More specifically, the collar 39 has, at its lower end, a bent portion 3 which is previously engaged with the flange portion 15 of the pressure receiving side connection port body 2.
9a is formed, and from the hexagon nut portion 5 to the color 39
Is inserted until the bent portion 39a comes into contact with the flange portion 15, and then the step 32a formed at the corner of the cap portion 32 is formed at the upper end.
By applying a deforming force toward the step 32a to engage the same with the step 32a, the pressure receiving side connecting port body 2 and the signal receiving side connecting port body 4
The spaces are connected.

In the figure, 1a is an O-ring for sealing between members, and 39a is an engaging portion at the tip of a color for engaging the step 32a. When assembling such a pressure sensor, first, for example, the pressure receiving side connection port body 2 and the intermediate body 3 are assembled.

This is because the tip of each terminal piece 13 and the recess 24 are
And the large diameter portion 17 of the intermediate body 3 is fitted to the circumferential side of the strain gauge 9 of the pressure receiving side connection port body 2 from this state.

According to this fitting, the tips of the terminal pieces 13 are inserted into the recesses 24 and are brought into sliding contact with the conductive portions 25 at the edges of the printed board 21. When the intermediate body 3 is inserted until it comes into contact with the flange portion 15, the assembling between the two parts of the pressure side connection port body 2 and the intermediate body 3 is completed, and the electrical connection between the strain gauge 9 and the printed circuit board 21 is completed. Connection is made.

Then, the signal receiving side connection port body 4 is assembled to the intermediate body 3. This is the direction in which the insertion portion 38b is,
The cap portion 32 of the signal receiving side connection port body 4 is fitted into the small diameter portion 18 of the intermediate body 3 in accordance with the orientation of the receptacle portion 26.

As a result, the pair of protrusions and recesses 34 on the inner bottom surface of the cap portion 32 have the step portion 3 in the intermediate body 3.
0, fit into the raised portion 18a. Then, using these as guides, the insertion portions 38b of the respective terminal portions 36 are inserted into the respective receptacle portions 26.

When the cap portion 32 is inserted until it abuts the stepped portion 30 and the raised portion 38b, the assembly of the signal receiving side connection port body 4 is completed, and the signal receiving side connection port body 4 is the intermediate body 3.
To the pressure receiving side connection port body 2 via.

As a result, the pressure receiving side connection port body 2, the intermediate body 3, and the signal receiving side connection port body 4 have the same diameter and are arranged in series.
Then, the collar 39 is fitted from the side of the hexagonal nut portion 5 and the collar 39 is inserted until the bent portion 39 a comes into contact with the collar portion 15.

After that, the upper end of the color 39 is deformed,
By engaging with the step portion 32a in the cap portion 32, the pressure sensor is assembled as shown in FIGS. 1 and 4. When using such a configured pressure sensor,
After the hexagonal nut portion 5 is screwed into a portion requiring pressure detection, for example, a detection port portion of an air conditioning pipe and a pressure sensor is attached, the terminal portion 36 is connected via a connector (not shown). Then, the external device may be electrically connected.

As a result, the pressure in the pipe is detected by the strain gauge 9 which is distorted by the displacement of the diaphragm 8. This output voltage is amplified by the amplifier circuit mounted on the printed circuit board 21,
The output voltage is output as a detected pressure value from the terminal unit 36 to the outside.

At this time, according to the conventional pressure sensor, the solder connecting the strain gauge 9 of the printed circuit board 21 is peeled off or a crack is generated in the solder under the influence of the vibration and shock generated in the diaphragm 8. I was worried that
According to the invention, this is not the case.

That is, in the pressure sensor of the present invention, the printed circuit board 21 is provided not in the strain gauge 9 but in the intermediate body 3 which is separate from the strain gauge 9. The vibrations and shocks generated at 1 are not directly transmitted to the printed board 21.

In addition to this, between the printed circuit board 21 and the strain gauge 9, there are two sliding members such as the terminal piece 13 and the conductive portion 25 which are slidable in the direction in which the diaphragm 8 is displaced. Since they are electrically connected to each other, the vibration and shock generated in the diaphragm 8 are not connected to the terminal piece 13 and the conductive portion 2.
The stress generated in the printed circuit board 21 by being absorbed by the relative displacement with respect to 5 is suppressed to a minimum.

This means that the printed circuit board 21 is protected from the vibration and shock generated in the diaphragm 8. Therefore, it is possible to prevent the solder soldered to the printed circuit board 21 from peeling off or cracking as in the conventional case.

As a result, from the strain gauge 9 to the printed circuit board 2
The conductive path up to 1 can be maintained well, and the reliability of the pressure sensor is improved. Moreover, the structure is simple because the conductive portion 25 provided on the printed board 21 and the terminal piece 13 protruding from the strain gauge 9 are brought into sliding contact with each other.

The printed board 2 fixed to the intermediate 3
1 and the signal receiving side connection port body 4 are electrically connected to each other, the intermediate body 3 is provided with the receptacle portion 26, and the leaf spring portion 27 is provided between the receptacle portion 26 and the printed board 21.
By adopting a structure in which the insertion piece 38 protruding from the inner surface of the cap portion 32 is inserted into the receptacle portion 26, the impact generated at the time of connection on the signal receiving side is not affected by the leaf spring. It is absorbed by the displacement of the portion 27 and does not reach the printed circuit board 21.

Moreover, the receptacle portion 26 and the insertion piece 38
The signal receiving side connection port body 2 and the intermediate body 3 are positioned with respect to each other by using the projection provided on the intermediate body 3, the raised portion 18a, and the recessed portion 34 provided on the inner bottom surface of the cap portion 32 mating with these as a guide. It is easy because you only have to assemble and.

Further, a gate is directly attached to the surface of the diaphragm 8.
Adopting the strain gauge 9 for forming the dip pattern 11 allows the strain gauge 9 to be installed on the diaphragm 8 with high accuracy without causing problems such as peeling, which also brings high reliability to the pressure sensor. it can.

8 and 9 show a second embodiment of the present invention. In this embodiment, the pressure sensor having the screw type pressure receiving side connection port body 2 for showing in the first example is changed from the pressure sensor having the male screw type pressure receiving side connection port body 40 without the need for an adapter. It can be changed to a sensor.

That is, normally, when a pressure sensor having a female thread type pressure receiving side connection port body 2 is changed to a female thread type, the hexagonal nut portion 5 at the tip is provided with an adapter having a male thread portion. However, in this case, a gap in which the fluid leaks may occur between the connected members, and it can be seen that the entire length of the pressure sensor is increased by the amount corresponding to the adapter.

Therefore, in the second embodiment, the diaphragm 8
And the size of the strain gauge 9 was not changed, and the male screw type pressure receiving side connection port body 40 was integrally formed by forging. That is, in the pressure receiving side connection port body 40, as shown in FIG. 9, for example, a metal block 41 such as a SUS or aluminum alloy formed in a cylindrical shape is forged, and a diaphragm 43 having a predetermined outer shape is first formed. A pressure receiving side connection port body 40 having a rough outer shape having a passage 44 corresponding to the size of the diaphragm 43 and a pressure introduction port 45 corresponding to the size of the passage 44 is formed.

Next, the tip of the mouth portion 45 of the pressure receiving side connection mouth 40 is drawn to make the passage 44 into a bag shape, and the outer diameter of the pressure inlet 45 corresponds to the diameter of the male screw. Shape to size.

After that, each part of the pressure receiving side connection port body 40 is subjected to a chamfering process, and a screw is processed on the outer peripheral part of the port part 46 in which the pressure introducing port 45 is formed to obtain a predetermined outer shape. After processing and finishing, a male screw type pressure receiving side connection port body 40 is formed.

That is, the male screw type pressure receiving side connection port body 40 is manufactured by using a forging process of a metal member to form the diaphragm 4
3 is formed into a bag-like passage 44 having a large passage end facing the pressure passage 3 and a small passage end communicating with the pressure introducing port 45, and a screw portion is formed on the outer peripheral portion of the mouth portion 46.

That is, by making the shape of the bag, it is not necessary to change the diameter of the diaphragm, so that the sensitivity of the strain gauge 9 is not reduced. When such a pressure receiving side connection port body 40 is used, a pressure sensor having a threaded portion at the tip thereof can be assembled without the need for an additional adapter.

Therefore, there is no possibility of forming a gap as seen in the structure of assembling the screw type pressure receiving side connection port body using the adapter, and there is no fluid leak. Moreover, the total length of the pressure sensor can be small because the adapter is not used.

Further, when molding the pressure receiving side connection port body 40, as shown in FIG. 9, the main body part 47 of the pressure receiving side connection port body 40 is concentrically formed with the outer peripheral part of the body part 47. Overhang, intermediate body 3, cap portion 32 of signal receiving side connection body 4
It is also possible to form a thin metal cylindrical body 48 capable of covering the periphery of the above to form a color.

With the pressure receiving side connection port body 40 having such a tubular body 48, the pressure receiving side connection port body 40 is covered with the tubular body 48 so as to cover the periphery of the intermediate body 3 and the signal receiving side connection port body 4. 8 is combined with the end side of the signal receiving side connection port body 4, the end portion of the tubular body 48 is deformed, and the same portion is engaged with the outer peripheral portion of the step 32a of the cap portion 32. As shown in the drawing, the pressure receiving side connection port body 40, the intermediate body 3, and the signal side connection port body 4 can be connected together without the need for a separate connecting means, that is, a color.

However, reference numeral 48a indicates an engaging portion which engages with the step 32a. In FIG. 8, the same parts as those in the first embodiment are designated by the same reference numerals and the description thereof is omitted.

[0086]

As described above, according to the first aspect of the present invention, the electrical connection between the strain gauge and the printed circuit board is realized without being affected by the vibration and shock generated in the diaphragm. can do.

As a result, the conductive path from the strain gauge to the printed circuit board can be maintained well, and a highly reliable pressure sensor can be provided. According to the invention of claim 2,
The effect of claim 1 can be realized with a simple structure.

According to the invention of claim 3, claim 1
In addition to the above effect, there is an effect that the printed circuit board and the signal side connection port body can be connected without applying stress to the printed circuit board.

According to the invention of claim 4, claim 1
In addition to the above effect, there is an effect that the strain gauge can be provided on the diaphragm with high accuracy and without any installation problem such as peeling.

According to the invention of claim 5, claim 1
In addition to the above effect, it is possible to realize a male thread type pressure sensor having no leak and having a short total length. According to the invention described in claim 6, in addition to the effect of claim 5, the pressure receiving side connection port body, the intermediate body, and the signal side connection port body are combined without the need for a separate connecting means. It has the effect of being able to.

[Brief description of drawings]

FIG. 1 is a perspective view showing an appearance of a pressure sensor according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view in which the pressure sensor is disassembled.

FIG. 3 is a perspective view showing a structure of each part of the disassembled intermediate body together with a mounted printed circuit board.

FIG. 4 is a sectional view of the entire pressure sensor.

FIG. 5 is a cross-sectional view of disassembled parts of the pressure sensor.

FIG. 6 is a cross-sectional view around an intermediate body viewed from different directions.

FIG. 7 is a cross-sectional view for explaining the structure of a strain gauge shown by enlarging a portion A in FIG.

FIG. 8 is a sectional view showing a pressure sensor according to a second embodiment of the present invention.

FIG. 9 is a diagram for explaining a method of manufacturing a pressure receiving side connection port body that constitutes the male thread type pressure sensor.

FIG. 10 is a cross-sectional view for explaining the installation structure of the printed circuit board in the conventional pressure sensor.

[Explanation of symbols]

1, 40 ... Pressure receiving side connection port body 3 ... Intermediate body 4
... Signal receiving side connection body 6,45 ... Pressure introduction port 7,44 ... Passage 8,43
... Diaphragm 9 ... Strain gauge 11 ... Gauge pattern 13 ...
Terminal piece (sliding member) 17 ... Large diameter part 18 ... Small diameter part 21
... Printed circuit board 22 ... Seat 23 ... Lever piece 23a
... Projection 25 ... Conductive part (sliding member) 26
... Receptacle part 27 ... Leaf spring part (conductive member) 35 ... Device accommodating chamber 36 ... Terminal part (terminal) 38 ... Insertion piece (insertion part) 48 ... Cylindrical body 48a ... Engagement part.

Claims (6)

[Claims] 1. A pressure receiving side having an end face having a diaphragm that is displaced by receiving pressure from a pressure introducing port, and a strain gauge for detecting strain of the diaphragm on the surface of the diaphragm. The connection port body, a short tubular intermediate body provided on the end face portion of the pressure receiving side connection port body so as to surround the peripheral side of the strain gauge, and the above-mentioned cover body covering the opening of the intermediate body. A signal side connection port body which is provided in combination with the end face side of the pressure receiving side connection port body and which has a terminal capable of being connected to an external device, which forms a device housing chamber whose periphery is closed in the intermediate body. A first printed circuit board fixed to the intermediate body and arranged in the device housing chamber, on which electronic components are mounted, and a printed circuit board and a terminal of the signal side connection port body are electrically connected Between the strain gauge and the printed circuit board, A pressure, comprising: a second connecting portion electrically connected by sliding contact with two sliding contact members that are in sliding contact with each other in a direction substantially perpendicular to a direction in which the ear diaphragm is displaced. Sensor. 2. The second connection portion has a terminal piece extending in the strain gauge in a direction in which the diaphragm is displaced toward the printed circuit board, and the printed circuit board includes the terminal piece and the diaphragm. The pressure sensor according to claim 1, further comprising a conductive member that is slidably contacted in a direction substantially perpendicular to the displacing direction. 3. The first connection part has an insertion part in the signal side connection port body, which is electrically connected to the terminal and protrudes from a surface facing the opening of the intermediate body toward the intermediate body. The intermediate body has a receptacle portion into which the plug-in portion is inserted according to the mounting of the signal-side connection port body, and a displaceable conductive member that electrically connects the receptacle portion and the printed circuit board. The pressure sensor according to claim 1, further comprising a member. 4. The pressure sensor according to claim 1, wherein the strain gauge has a gauge pattern formed on a surface of the diaphragm. 5. The pressure receiving side connection port body is formed by forging a metal member, and has a bag shape in which an inner passage has a large passage end facing the diaphragm side and a small passage end communicating with the pressure introducing port. 2. The pressure sensor according to claim 1, wherein the pressure sensor is formed by forming a threaded portion on an outer peripheral portion of the mouth portion formed with the pressure introduction port. 6. The pressure-reception-side connection port body is a thin-walled metal tube that protrudes concentrically with the body on the outer periphery of the body part and covers the periphery of the intermediate body and the signal-reception-side connection port body. The tubular body has a cylindrical body, and the distal end portion of the cylindrical body is deformed,
The pressure sensor according to claim 5, further comprising an engaging portion that engages with an outer peripheral portion of the signal receiving side connection port body.